Electric switch



C. W. DENNY ELECTRIC SWITCH Patented Dec. 23, 1924.

CLAUDE WILLIAM DENNY, OF LONDON, ENGLAND.-

' ELECTRIC swxron;

Application flled June 24, 1922. Serial No. 570,680.

To all whom it may concern:

Be ,it known that I, CLAUDE WILLIAM DENNY, a subject of the King of Great Britain, and a resident of London, England, have invented certain new and useful Improvements in Electric Switches; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, and to the characters of reference marked thereon.

This invention relates to electric switches of the knife-blade kind having a quick break action and refers chiefly,tho ugh not. exclusively, to switches adapted to be placed within the handle of an electrically heated iron or other electrically operated or controlled device or appliance where economy of space is to be considered while maintaining the efficiency of the switch also wherein the opening and closing of the switch is controlled by the act of the user gripping, or releasing his or her grip from the handle of the device.

. The Switches controlled by the user by the act of gripping the handle of the device, and which automatically open when the grip is released, are subject to a greater amount of wear than ordinar switches owingto the more frequent operation and as arcing across the contacts will take place every time the switch is opened, ordinary switches, as hitherto constructed will, when so used, soon be come erratic and inefiicient or useless, furthermore, there is a force, usually a spring, constantly tending to open the switch and this force; has to be counteracted or overcome by the grip of the user, so that should the users fingers tire there is a likelihood of lilalfl switch being frequently opened acciden- 1:

tion toovercome these defects and drawbacks and to provide a switch wherein the pivoted "knife-blade member is furnished with a number of separate contacts in series y- It is the chief object of the present invenlight spring which acts 0.. the handle. Further a locking device is provided to act upon and lock the movable member in the closed position and is adapted to be released by or through the movement of the handle, or operating lever.

In accordance with this invention also the contacts are so contrived and arranged that breaking takes place between them all simultaneously. This is done by sloping or stepping the contacts of either or both series.

Referring to the accompanying drawmgsz- Fig. 1 is a sectional elevation of an electric iron in the handle of which the present invention is embodied, the switch being shown in the open position.

Fig. 2 is a sectional elevation of the han' dle shown in Fig. 1 and showing the switch in the closed position or a position occupied by the parts when firmly gripped by the user as when closing the switch.

Fig. 3 is a sectional elevation also of the handle shown in Fig. l, but showing the switch controlling lever or handle moved to its fully open position preliminarily to movement of the switch under pressure of its spring. 4

F Fig. 4 is an end section on the line 4-4 of lg. 5 is an end section on the line 5-5 of Fig. 3

Fig. 6 is an end view of the iron-handle showing the position of the leads and Fig.7 is a sectional view showing the looking device.

' Figs. 6 and 7 are drawn to than the other figures.

A is the "stationary contact member, B the movable contact blade, 0 the operating lever or handle, D the spring catch, E the spring acting on the contact blade and F the spring acting-upon the operating lever.

The stationary contact-carrying member a larger scale is conveniently in the form of a bar A disposed in a slot or recess 9 in the upper side of the handle G and secured to the handle at each end by screws 0. The. handle G is furnished with a removable part Gr secured to the main art of the handle G by a screw 9 so that y undoing this screw and remcving the part Gr the member A can be got 'at for repairs or inspection.

Projecting from the lower side of the bar A and into a reces g in the handle G are two 'U-shaped contact members A A and a double U-shaped contact member A these contacts being insulated from the bar A in any convenient manner.

The contact carrying blade B is pivoted at b to a post or block K which conveniently is carried by or attached to the underside of the plate A and projects into the recess 9 Mounted on the bar B are two contacts B B which are separate from each other and are insulated from the bar B in any convenient manner.-

Two terminal leads J 2 J 3 are brought from the usual heating element within the iron and led through openings in the end of the handle a wire J being led from the lead J 2 to the contact A and a similar wire J from the lead J to the contact A The spring E controlling the operation of the contact blade B is conveniently in the form of a comparatively strong coil spring one end of which is secured to the lower side of the bar A and the other end fits into a boss on the blade B.

The contact B on the blade B is ada ted in the closed position of the switch to orm a bridge piece between the contact A and one limb of the contact A while the contact B on the blade B forms a bridge piece between the second limb of the contact A and the contact A. As the switch will automatically open and the contacts be broken each time the user releases the grip as when bringing a fresh portion of the work to the iron or when obtaining a fresh piece of work arcing will take place frequently between the contacts andthe destructive influence of this arcing, by the present invention, is reduced b causing the arcing to take place at the our points arranged in series.

As the blade B is pivoted and therefore moves through an arc of a circle it is necessary to rovide means whereby the contacts will be roken at all points simultaneously. This is accomplished according to the present embodiment of the invention by sloping the stationary contacts A A A so that the contact A is longer than the contact A and the contact A longer than the contact A. The same effect may be produced by sloping or tapering the contacts B, B or by sloping or stepping the contacts of both series.

The 0 erating lever G is pivoted at 0 to the bloc or post K within the recess 9 in the handle G and is itself adapted in the closed position of the switch, to be accommodated within this recess so that its other' portion conforms practically to the shape of the handle G (see Fig. 2). The inner side of the lever C is recessed to accommodate or receive the blade .B both in the closed and open ositions of the switch (see Figs. '1 and 2 In the recessed part of the lever C is a block C which acts as a stop piece for the blade B which latter is operated by the spring E and this block presses on the blade B to close the switch when the handle G and lever C are gripped by the user.

Acting upon the lever C and constantly tending to push it outward is the spring F one end of which is anchored to a pin on the post K and the other end is secured to a pin on the lever C. This spring is of sufiicient strength to move the lever on its pivot when the latter has been released or partially released by the user but is of less power than the spring E acting upon the blade B.

In order that the users hand may not be unnecessarily strained or tired through having to grip hard enough to overcome the power of the spring E and also in order to place flthe exact point of breaking contact out of the direct control of the user and thus prevent a slow breaking action there is rovided the locking device above referre to. This locking device comprises a catch D which is mounted to slide in grooves in the post K and is held in its forward position to engage a nose or shoulder B on the blade B by a spring 03 (see Figs. 1 and 7).

At the rear the catch D has two shoulders D which project from the opposite sides of the catch and are adapted tobe engaged by the walls of cam slots C formed on the rear end of the lever C. This catch holds the blade B in the closed position and'the lever C can turn on its pivot under the action of the sprin F to a limited extent without permittin t e cams to withdraw the catch D and re ease the blade B so that the user need not ip the handle and press the lever C Wlien the lever C is entirely released from the users grip the spring F moves the lever C outward to the fullest extent of its movement as in Fig. 3, the cam then withdraws the catch D. The spring E will then move the blade B around its pivot to make a quick break.

I claim 1. In an electric switch the combination of a stationary member, a pivoted knife-blade member, a number of separate contacts on the stationary member, a number of separate. contacts on the knife-blade member the contacts of one member connecting those of the other member in series, an operating lever for the knife-blade member, a relatively weak spring, adapted to act upon the operating lever, and a relatively strong spring adapted to act upon the knife-blade member.

2. In an electric switch the combination with a stationary member, a pivoted knifeblade member, and an operating lever for the knife-blade member, of a number of separate contacts on the stationary member, a number of separate contacts on the knifeof the companion member in series, a relatively weak spring adapted to act on the operating lever, a relatively strong spring adapted to act on the knife-blade member, and means for locking the knife-blade member in position to close the switch.

3. In an electric switch, the combination with a stationary member, a pivoted knife-- blade member, and an operating lever for the knife-blade member, a number of separate contacts on one of the aforesaid members, a number of separate stepped contacts on the other member, the said contacts of both members interconnecting in series upon "closing of the knife-blade member, a relatively weak spring adapted to act on the operating lever and a relatively strong spring adapted to act on the knife-blade member.

4. An electric switch comprising a stationary member, a block carried thereby, a knife blade member pivoted to the block, a catch movably carried bythe block and releasably engaging the knife blade member to hold itclosed, and a lever pivoted on the block for closing the knife blade member and adapted to act upon the catch, upon opening movement of the lever, for rendering the catch inoperative.

5. In an electric switch, the combination with a stationary member, a pivoted knifeblade member and an operating lever for the knife-blade member, of a number of separate contacts in series on one of the members, a number of separate contact members in series on the other member, a relatively strong spring'adapted to act on the knifeblade member, a relatively weak spring adapted to act on the operating lever, a slidable catch adapted to act upon the knifeblade member, a spring, acting upon the catch, and means on the operating lever for withdrawing the catch from the knife-blade member.

6. In an electric switch the combination with a stationary member, a pivoted knife,-

blade member, and an operating lever, act? ing on the knife-blade member, of a number of separate contacts in series on the stationary member, a number of separate contacts arranged stepwise in series on the knifeblade member, a relatively strong spring adapted to act upon the knife-blade member, a relatively weak spring adapted to act upon the operating lever, a slidable catch adapted to act upon the knife-blade'meinher, a spring controlling the catch, and

means on the operatin lever and interlocking with the catch 3 or withdrawing the catch. 7

7. In an electric switch the combination of a stationary contact carrying member, a

ivoted contact carrying member, an operating lever for the pivoted member, a relatively strong spring acting upon the pivoted member, a relatively weak spring acting upon the pivoted lever, a catch acting upon the 1 pivoted member and means on the end of the within the handle of the iron, a number of separate contacts in series on the stationary member, leads connected to the terminal contacts of the series, a pivoted knife-blade member working in a recess in the handle, a number of separate contacts in series on the pivoted member, an operating lever recessed to embrace the pivoted member, a

,relatively strong spring acting on the pivoted member and a relatively weak spring acting on the operating lever.

9. In an electric iron in combination therewith a contact-carrying member fixed withinthe handle of the iron, a pivoted member adapted to move in an opening in the'handle of the iron, a: pivoted operating lever, working in the said opening and recessed to embrace the pivoted member, a number of separate contacts in series on the stationary member, leads connected to the terminal contacts of the series, a num ber of separate contacts in series on the pivoted member, a relatively strong spring acting upon the pivoted member, a relatively weak spring acting upon the pivoted lever and means for locking the pivoted member in position to close the switch.

10. In an electric iron and in combination therewith, a stationary member fixed with in an opening in the handle, a pivoted member adapted to move within the opening in the handle, a pivoted operating lever, also working in the said 0 ening, and recessed to embrace the pivote member, a number of separate contacts in series upon one member, a number of separate contacts arranged in-stepped series on the other member and means for moving the pivoted member from the handle opening into the recess of the lever upon opening of the switch.

11. An electric switch comprising a stationary contact member, a second contact member normally under tension to open and movably connected therewith, a slidable catch connected to the first member, and an operating device for the second member, interlocking with a part of the catch for camming thereagainst to render the catch ino rative by and during movement of said device to its inoperative position.

12. An electric switch comprising a handle having a recess, a contact support in the handle. recess, a movable contact pivoted,

connected to the handle and having connection with the catch to operate the same,

and a coiled spring connected to the outer end portion of the lever and to a fixed point ofiset relative to the pivotaltmountmg of said lever.

13. In an electric iron, and in combination therewith, a stationary contact carrying member fixed within the handle of the iron, a number of separate contacts in series on the stationary member, leads connected to the terminal contacts of the series, a movable member working in a recess in the handle, a number of separate contacts in series on the movable member, an operating member recessed to embrace the movable member, a relatively strong spring acting on the movable member and a relatively weak spring acting on the operating member.

14. The combination with a tool handle having a recess therein; of a switch comprising a stationary contact member fixed within said recess, a movable contact member working in said recess, an independently movable operating member recessed to embrace said movable member and having a tendency to occupy a position at which said contact members will be in disconnected relation, and retarded means controlled by said operating member for disconnecting said contact members.

15. The combination with a tool handle having a recess therein; of a switch comprising a stationary contact member fixed within said recess, a movable contact mem- I ber working in said recess, an operating member recessed to embrace said movable member and having a tendency to occupy a position at which said contact members will be in disconnected relation, and said movable contact member being normally under tension to separate itself from said stationary member which tension is relatively greater than the aforementioned tendency of said operating member.

16. The combination with a tool handle having a recess therein; of a switch comprising a stationary contact member fixed .within said recess, a movable contact member working in said recess, an operating member recessed to embrace said movable member and having a tendency to occupy a position at which said contact members will be in disconnected relation, said movable contact member being normally under tension to separate itself from said stationary member which tension is relatively greater than the aforementioned tendency of said operating member, latching means for said movable member, and releasing means for said latching means controlled by said operating member.

CLAUDE WILLIAM DENNY 

